title: Influence of lean and fat mass on bone mineral density and on urinary stone risk factors in healthy women.
abstract: BACKGROUND
  The role of body composition (lean mass and fat mass) on urine chemistries and bone quality is still debated. Our aim was therefore to determine the effect of lean mass and fat mass on urine composition and bone mineral density (BMD) in a cohort of healthy females.
  
  
  METHODS
  78 female volunteers (mean age 46 ± 6 years) were enrolled at the Stone Clinic of Parma University Hospital and subdued to 24-hour urine collection for lithogenic risk profile, DEXA, and 3-day dietary diary. We defined two mathematical indexes derived from body composition measurement (index of lean mass-ILM, and index of fat mass-IFM) and the cohort was split using the median value of each index, obtaining groups differing only for lean or fat mass. We then analyzed differences in urine composition, dietary intakes and BMD.
  
  
  RESULTS
  The women with high values of ILM had significantly higher excretion of creatinine (991 ± 194 vs 1138 ± 191 mg/day, p = 0.001), potassium (47 ± 13 vs 60 ± 18 mEq/day, p < 0.001), phosphorus (520 ± 174 vs 665 ± 186 mg/day, p < 0.001), magnesium (66 ± 20 vs 85 ± 26 mg/day, p < 0.001), citrate (620 ± 178 vs 807 ± 323 mg/day, p = 0.002) and oxalate (21 ± 7 vs 27 ± 11 mg/day, p = 0.015) and a significantly better BMD values in limbs than other women with low values of ILM. The women with high values of IFM had similar urine composition to other women with low values of IFM, but significantly better BMD in axial sites. No differences in dietary habits were found in both analyses.
  
  
  CONCLUSIONS
  Lean mass seems to significantly influence urine composition both in terms of lithogenesis promoters and inhibitors, while fat mass does not. Lean mass influences bone quality only in limb skeleton, while fat mass influences bone quality only in axial sites.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Parma, Via A, Gramsci 14, Parma 43126, Italy. antonio.nouvenne@alice.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Nouvenne
authors.forename: Andrea
authors.initials: A
authors.lastname: Ticinesi
authors.forename: Angela
authors.initials: A
authors.lastname: Guerra
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Folesani
authors.forename: Franca
authors.initials: F
authors.lastname: Allegri
authors.forename: Silvana
authors.initials: S
authors.lastname: Pinelli
authors.forename: Paolo
authors.initials: P
authors.lastname: Baroni
authors.forename: Mario
authors.initials: M
authors.lastname: Pedrazzoni
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lippi
authors.forename: Annalisa
authors.initials: A
authors.lastname: Terranegra
authors.forename: Elena
authors.initials: E
authors.lastname: Dogliotti
authors.forename: Laura
authors.initials: L
authors.lastname: Soldati
authors.forename: Loris
authors.initials: L
authors.lastname: Borghi
authors.forename: Tiziana
authors.initials: T
authors.lastname: Meschi
mesh_terms: D050154:Adiposity; D015519:Bone Density; D004032:Diet; D016002:Discriminant Analysis; D005260:Female; D006262:Health; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008875:Middle Aged; D015203:Reproducibility of Results; D012307:Risk Factors; D014545:Urinary Calculi / Q000453:epidemiology* / Q000503:physiopathology*